Case Study: 95 Twin Screw Extruder with Cobalt-Based Tungsten Carbide Barrel Sleeve

Introduction

In high-performance extrusion applications, the barrel sleeve plays a decisive role in ensuring stability, durability, and efficiency. Recently, ZHITIAN successfully delivered a cobalt-based tungsten carbide (Co-WC) barrel sleeve for a 95 twin screw extruder, adopting advanced Cold Isostatic Pressing (CIP) technology. This breakthrough demonstrates the superior wear resistance and toughness of our self-developed ZT818 material.

Industries That Benefit Most from ZT818 Alloy Barrel Inserts

ZT818 cobalt-based tungsten carbide alloy is specifically engineered for extreme wear and demanding processing environments. It provides outstanding performance in applications such as wood-plastic composites (WPC), high-filler plastic extrusion, rubber compounding, lithium battery and solid-state battery material mixing, as well as corrosive and abrasive chemical extrusion. Its ultra-high hardness (HRC68–69) and wear resistance deliver extended service life and reduced downtime, making it the preferred choice for industries where conventional barrel liners frequently fail.

Material Highlights

The ZT818 cobalt-based tungsten carbide sleeve is composed of 82% tungsten carbide and 18% cobalt binder. Through cold isostatic pressing and precise sintering, the product achieves outstanding properties:

• Hardness: HRC 68–69
• Impact Toughness: ＞13 J/cm²
• Exceptional Wear Resistance: Significantly higher than conventional high-speed tool steels or ceramic-metal composites

With this performance, ZT818 has become the “benchmark material” for extreme wear resistance, often described as the “ceiling of metal-ceramic performance.”

Wear Test – Rubber Wheel Abrasion Test

To validate its performance, ZT818 was tested against the standard high-speed tool steel 6542 using a rubber wheel abrasion method (10 min test).

The results show that ZT818 exhibits more than 20 times the wear resistance of 6542, highlighting its unmatched durability under abrasive extrusion conditions.

Application Case – 95 Twin Screw Extruder

The ZT818 sleeve has been successfully applied to a 95mm twin screw extruder for high-fill and high-wear processing. The combination of ultra-high hardness, superior toughness, and outstanding wear resistance ensures long service life and stable operation, significantly reducing maintenance frequency and cost for the customer.

Application Scenarios

ZT818 cobalt-based tungsten carbide barrel sleeves are ideal for ultra-high wear extrusion conditions and processes requiring low material contamination, including:

• Lithium battery slurry mixing – ensuring purity in cathode/anode materials
• Future solid-state battery applications – meeting stricter requirements for wear resistance and contamination control
• Wood-plastic composites (WPC) – resisting heavy abrasion from high wood fiber content
• High filler, high-shear extrusion processes – where conventional liners suffer frequent replacement

In these demanding environments, ZT818 offers extended service life, reduced downtime, and consistent product quality.

Conclusion

With the successful application of ZT818 cobalt-based tungsten carbide barrel sleeves, ZHITIAN once again demonstrates its leadership in material innovation and extrusion solutions. For industries handling highly abrasive or contamination-sensitive materials, ZT818 provides a cost-effective, high-performance solution that maximizes efficiency and equipment longevity.

FAQ – ZT818 Cobalt-Based Tungsten Carbide Barrel Sleeve

Q1: What makes ZT818 different from conventional metal-ceramic materials?
A1: ZT818 combines 82% tungsten carbide with 18% cobalt binder using cold isostatic pressing (CIP), achieving hardness up to HRC 68–69 and toughness ＞13 J/cm². Compared to traditional metal-ceramics, it provides higher toughness and better resistance to cracking, making it more reliable in heavy-duty extrusion.

Q2: How much longer is the service life compared to standard tool steels?
A2: In rubber wheel abrasion tests, ZT818 showed over 20 times the wear resistance of high-speed tool steel 6542. This means significantly longer service life, reduced downtime, and lower replacement frequency.

Q3: Can ZT818 reduce material contamination in sensitive industries like batteries?
A3: Yes. Thanks to its stable microstructure and superior wear resistance, ZT818 minimizes metal debris, making it highly suitable for lithium battery slurry mixing and solid-state battery applications, where contamination control is critical.

Q4: Is customization available for different extruder models?
A4: Absolutely. ZHITIAN provides customized barrel sleeves in terms of diameter, geometry, and structure to match different twin screw extruder models and processing conditions.